Description
Check if a proposition in postfix form is a tautology, for example, pp~+ (that is, p\/~p) is a tautology, while qq~*r+ (q/~q)\/r is not.
Input
The first line is an integer N(<=1000).
Then there are N lines of propositional formulas with postfix form, where '~' represents negation, '*' represents conjunction and '+' represents disjunction. Propositional variables are lower case letters.
Output
For each formula, output the formula, then a colon ':' and "Yes" or "No" on one line depending on if the formula is a tautoloty.
Sample Input
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4
p
pq~p~**~
pq+
p~p+
Sample Output
p:No
pq~p~**~:Yes
pq+:No
p~p+:Yes
这是我的代码,但是不知道哪里出问题了,谁能帮看一下
http://soj.sysu.edu.cn/viewsource.php?cid=971&sid=2337569
